Koyo Aluminum Performance Radiator for 12-15 Civic Si K24Z7

Koyorad Aluminum Racing Radiator KH082661 - 2012-2015 Honda Civic Si (9th Gen, K24Z7)

If you track or hard-drive your 9th gen Civic Si, the factory radiator is the weak link waiting to let you down. Those OEM plastic end tanks get brittle with age and heat cycling, and one day they just crack and dump your coolant, usually at the worst possible moment. On top of that, the stock core simply doesn't hold enough coolant to keep temps in check during sustained high-load running. This Koyorad all-aluminum radiator, part number KH082661, is the direct fix. It's a thicker, higher-capacity core wrapped in a fully welded aluminum housing, and it drops straight into your factory location.

Why Your K24Z7 Runs Cooler With This

The heart of it is Koyo's 25mm Hyper Core, which is roughly 50% thicker than your stock radiator. That translates to a lot more coolant volume and a lot more surface area to shed heat. It's the difference between your K24Z7 holding a steady, happy temperature through back-to-back pulls or a full track session, versus watching the needle creep toward trouble lap after lap. And because the whole thing is all-aluminum and TIG-welded by hand, you finally ditch the failure-prone plastic tanks that eventually crack on these cars. No more sweating the OEM radiator giving out on you.

A True Bolt-In For The 2012-2015 Si

Koyorad built this radiator to OEM dimensions, so it's a genuine direct replacement on the 2012, 2013, 2014, and 2015 Civic Si, coupe and sedan alike. It reuses your factory fans, fan shroud, radiator hoses, and AC condenser, with no cutting, drilling, or fabrication anywhere. You drain the coolant, pull the stock radiator, and set the Koyo unit into the same mounts. The filler neck and drain plug are CNC-machined aluminum, and the finish is clean enough that it actually looks the part in a dressed-up bay instead of hiding behind the bumper.

One Thing You Have To Order With It

Read this before you check out, because it'll save your install day. This radiator does not work with your factory radiator cap. You need a Koyo SK-C13 cap, sold separately, to seal and pressurize the system correctly. Add one to your cart now so you're not stuck halfway through the job waiting on a part. It's a small piece, but without it you're not finishing the swap.

Who This Is For

This one's for the Si owner who asks more of the car than a commute. Whether you're running track days, chasing cones at an autocross, or just done trusting a 10-year-old plastic radiator on spirited backroad drives, this Koyorad aluminum radiator gives you the cooling headroom and the peace of mind the factory piece can't. Bolt it in, grab the SK-C13 cap, and stop thinking about your coolant temps.

Part number: KH082661. Brand: Koyorad. Type: All-aluminum performance radiator, TIG-welded. Core: 25mm (1 inch) high-density Hyper Core, about 50% thicker than stock. Fits: 2012-2015 Honda Civic Si (9th gen, FB/FG), coupe and sedan. Engine: K24Z7 2.4L. Transmission: Manual. Install: Direct bolt-in, retains OEM fans, shroud, hoses, and condenser. Required cap: Koyo SK-C13 (sold separately, OEM cap not compatible).